Oxygen-incorporated Ge2Sb2Te5 (GST) films were deposited using ion beam sputtering deposition. Sheet resistance in films with 16.7% oxygen content decreased at a higher annealing temperature than that of undoped GST films, while resistance in films with an oxygen content of over 21.7% decreased dramatically at lower temperatures. X-ray diffraction patterns showed crystallization to face-centered cubic phase was suppressed. However, phase separation to a hexagonal structure was observed in films with an oxygen content of over 21.7%. Extended x-ray absorption fine structure data of GeK edge showed Ge was bonded to O as well as Te. Moreover, a stoichiometric GeO 2 phase was not observed, while phase separation into Sb2 O3 and Sb2 Te3 occurred. The results indicate Ge-Te bonds with oxygen are related to structural stability.
Bibliographical noteFunding Information:
This research was supported by the National Research Project for PRAM Development sponsored by the Korean Ministry of Commerce, Industry, and Energy.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)